This invention relates to an information processor having a multi-window display function and capable of executing various types of controls by function keys and the like.
As is well known, various types of information processors based on multi-task and multi-window display systems have been developed. The multi-window system is discussed in "News Preliminary Technical Overview", Oct. 1986, by Sun Microsystems Inc., and by Gettys J., "Problems Implementing Window Systems in UNIX", 1986 Winter USENIX Technical Conference Proceedings, Jan. 1986.
When the multi-window display is performed using this type of information processor, a plurality of windows are often displayed, overlapping each other. Also in this case, the right to use the keyboard is given to the uppermost (top) window of those overlapping windows on the CRT screen. Information entered from the keyboard is input to the top window. To enter information into windows other than the top window, the overlapping order (hereinafter referred to simply as the "order") of the windows must be changed so that the window to be keyed-in the information is located at the top in the CRT screen. In other words, some operation to give the right of the keyboard-use to the desired window is needed before information is keyed in.
An information processor with a multi-task function is frequently operated in a multi-mode, in which windows are assigned to various tasks, respectively. In such operation, a plurality of windows displayed frequently overlap each other, because of the limited size of the CRT screen.
To enter information into each window, the processing information of the task associated with the window is keyed in by function keys on the keyboard. Accordingly, the window displays the processing information assigned to the function keys.
In some situations, an operator may desire to enter processing information by the function keys to a window which is not the top window, and without changing its order. For example, in an information processor of the type in which information is retrieved from an optical disk apparatus, and the retrieved information is to be displayed, the information that the operator desires is retrieved from the optical disk apparatus by accessing functions in the first window, and the retrieved information is then displayed in the second window, which may be displayed above (on) or below (under) the first window. In order that the second window successively displays the plural pieces of information which are retrieved by accessing functions in the first window, the first or second function key, for example, must be used for entering the information to the first window. "The first function key in the first window" functions to display the information succeeding the information being currently displayed in the second window. "The second function key" functions to display the information preceding the currently displayed information.
In the conventional information processor, only the top window has the right to use keyboard keys including the function keys, and the right to use only the function keys cannot be applied to other windows. To give the right of the function keys use to another window, the order of that window must be set to the top. To change the window order, many CRT screens must be updated, and this updating takes much time. Thus, in order to display the next information, every time the first function key is to be input to the first window, the first window must become the top window. To see the information image in the second window, the operator must again execute the operation to change the second window to the top window. This is time consuming and troublesome work.